Social networks have around 2 billion internet users worldwide. Facebook has around 500 million users globally, with around half being active on a regular basis. Most Facebook users also have at least one other local social network account. Twitter and Facebook are in the top 25 websites that refer traffic to other sites, and in the top 10 referrers for most sites. Social networks are also influencing politics, with politicians and campaigns using platforms like Facebook and Twitter to engage with voters. However, privacy is a growing issue, as information shared publicly on social networks does not always mean users want that information to be widely publicized or distributed.